Development and evaluation of a clinical decision support system for early diagnosis of acute appendicitis.

The most frequent reason for individuals experiencing abdominal discomfort to be referred to emergency departments of hospitals is acute appendicitis, and the most frequent emergency surgery performed is an appendectomy. The purpose of this study was to design and develop an intelligent clinical decision support system for the timely and accurate diagnosis of acute appendicitis. The number of participants which is equal to 181 was chosen as the sample size for developing and evaluating neural networks. The information was gathered from the medical files of patients who underwent appendicectomies at Shahid Modarres Hospital as well as from the findings of their appendix samples' pathological tests. The diagnostic outcomes were then ascertained by the development and comparison of a Multilayer Perceptron network (MLP) and a Support Vector Machine (SVM) system in the MATLAB environment. The SVM algorithm functioned as the central processing unit in the Clinical Decision Support System (CDSS) that was built. The intelligent appendicitis diagnostic system was subsequently developed utilizing the Java programming language. Technical evaluation and system usability testing were both done as part of the software evaluation process. Comparing the output of the optimized artificial neural network of the SVM with the pathology result showed that the network's sensitivity, specificity, and accuracy were 91.7%, 96.2%, and 95%, respectively, in diagnosing acute appendicitis. Based on the existing standards and the opinions of general surgeons, and also comparing the results with the diagnostic accuracy of general surgeons, findings indicated the proper functioning of the network for the diagnosis of acute appendicitis. The use of this system in medical centers is useful for purposes such as timely diagnosis and prevention of negative appendectomy, reducing patient hospital stays and treatment costs, and improving the patient referral system.

Flexing the neck relieves tension on cervical esophageal anastomosis.

BACKGROUND: The conventional method of bridging anatomic defects of the upper digestive tract in the neck is by tissue transfer--either gastric or colon pull-through, free jejunal graft, or full-thickness skin flaps. An alternative way of closing such defects is to flex the neck. This moves the remnant proximal esophagus or pharynx a considerable distance downwards--a standard tension-releasing maneuver in tracheal resection and reconstruction. METHODS: Neck flexion was used in 7 patients grouped into three separate surgical conditions: A) in two patients after esophagectomy, where the pulled-up stomach would not reach the remnant proximal esophagus or the pharynx; B) in three patients where the defect after removal of the diseased portion of the cervical esophagus measured 4.5, 5.0, and 8.0 cm, respectively; and C) in 2 patients with 4.5- and 1.5-cm long circumferential postoperative esophageal strictures managed by Heineke-Miculicz repair. RESULTS: No postoperative cervical fistulas were seen. One patient, whose 8-cm long cervical esophageal defect had been closed by end-to-end anastomosis, developed a stricture. CONCLUSION: In special situations, flexing the neck allows for safe anastomosis or closure of esophageal defects in the neck, obviating the need for tissue transfer.

Effects of Intraperitoneal Administration of Simvastatin in Prevention of Postoperative Intra-abdominal Adhesion Formation in Animal Model of Rat.

OBJECTIVE: To determine the preventive effects of local administration of simvastatin for postoperative intra-abdominal adhesion formation in animal model of rat. METHODS: In this experimental study, 32 Wistar albino rats as the animal model of intra-abdominal adhesion formation were included. Adhesions were induced in all the animals via abrasion of the peritoneal and intestinal surface during laparotomy. Afterwards, the rats were randomly assigned to receive simvastatin (30 mg/kg body weight) as a single intraperitoneal dose at the time of laparotomy (n=16) or normal saline in same volume at the same time (n=16). At the day 21, animals were euthanized and the adhesions were quantified clinically (via repeated laparotomy) and pathologically and compared between the two groups. RESULTS: The baseline characteristics of the animals were comparable between two study groups. Clinically, in simvastatin group, 10 rats (62.5%) did not develop any adhesion and 6 (37.5%) had first-grade adhesion; whereas in the control group, 11 (68.8%) rats had first- and 5 (31.2%) had second-grade adhesions (p<0.001). Pathologically, in simvastatin group, 6 rats (37.5%) had first-grade adhesion, while in control group, 11 rats (68.8%) had first- and 5 (31.2%) had second-grade adhesions (p<0.001). CONCLUSION: Our findings suggest that intraperitoneal administration of simvastatin is an effective method for prevention of postoperative intra-abdominal adhesion formation in animal model of rat.

A Safe Method of Tracheal Polyflex Stent Placement: A Review of 20 Patients.

BACKGROUND: Surgery is an appropriate therapeutic approach for tracheal stenosis due to various benign and malignant conditions. When surgery is postponed for certain reasons, other options are chosen for airway patency. One alternative is using airway stents. OBJECTIVES: We aimed to introduce a safe method of tracheal polyflex stent placement in patients with tracheal stenoses. PATIENTS AND METHODS: During a 7-year period (2002 - 2008), polyflex stents were used 29 times among 20 patients for various indications. After encountering many difficulties in earlier cases, we gradually developed our new method and used it in most of our patients. In this method, without using large rigid bronchoscopes, the introducer tube could be used as a bronchoscope with the aid of a zero-degree lens and ventilating apparatus. In this method, the rate of possible trauma to the airway can be minimized by avoiding the use of thick rigid bronchoscopies and the stent can be placed faster and more accurately. RESULTS: Polyflex stents were used in 11 men (55%) and 9 women with a mean age of 38.5 years. Stents were removed and changed in 12 cases and replaced with another type of stent in 3 patients. Indications were recurrence of tracheal stenosis (7), multisegmental tracheal stenosis (3), anesthesia limitations (3), tracheal tumors (2), dehiscence of tracheal anastomosis (1), severe inflammation of the tracheal mucosa (1), esophagobronchial fistula (1), and external pressure on the left main bronchus (1). In one patient, a stent was used to open a kinked Dumon stent as a temporary life-saving procedure. We found 6 cases of stent migration, 3 cases of granulation tissue formation, 1 case of infection, and 1 case of surgical site dehiscence. CONCLUSIONS: Stents would be regarded as a temporary means of reaching the ideal condition for resection and reconstruction in most patients with tracheal stenoses. Although an optimal stent has not been introduced yet, we used polyflex stents in most of our patients with tracheal stenosis due to its availability and ease of use. We suggest that this method is safe and less time consuming than its traditional method of placement.

Mediastinal lymphangioma in a child.

We report a case of a male child with a cystic mass in his left side of the neck with extension to the mediastinum. This article highlights the clinical and para-clinical findings and management of these cases. In conclusion, it is necessary to evaluate the mediastinum for extension of the cyst in cases with cystic hygromas of the neck. Surgical resection of the tumor through a cervical incision can be considered.

Primary major airway tumors; management and results.

OBJECTIVE: Primary major airway tumors are rare. A retrospective analysis of referral centers experience could be helpful for their management. METHODS: Fifty-one patients, including 44 (86%) malignant and seven (14%) benign with primary tumors of subglottis, trachea, carina, and main stem bronchi, were managed in a 14-year period. Based on computed tomography (CT) scan and rigid bronchoscopy findings, those who evaluated as resectable underwent airway resection and reconstruction. The others were managed by one or a combination of these methods: core out, laser, chemotherapy, radiotherapy, and tracheostomy. Follow-up was completed in 88.2%, mean (35.2 ± 33.2 months). RESULTS: Extraluminal extension of the tumor found in CT scan was significantly associated with unresectability (p = 0.006). Thirty-two patients underwent resection with three complications (9%) and one mortality (3%). Nineteen were managed by non-resectional methods; of these, 15 were found unresectable, because of tumor length, extensive local invasion or diffuse distant metastases, and four due to risk-benefit ratio or patient preference. Among 18 patients with adenoid cystic carcinoma 13 (72%) were resected (seven with negative margins). Overall 1-, 2-, 5-, and 8-year survival was 90.9%, 90.9%, 77.9%, and 19.5%, respectively. In unresectable tumors with adenoid cystic carcinoma, overall 1- and 2-year survival was 60% and 40%, respectively. Data analysis found significant association of long-term survival with resection (p = 0.005) but not with negative margins in adenoid cystic carcinoma. Among 15 patients with carcinoid tumors, all were alive at the end of follow-up, except one who died after surgery. CONCLUSIONS: Airway resection, if feasible, may extend survival and may even be curative, with low morbidity and mortality, in most patients with major airway tumors.

The etiological factors of recurrence after tracheal resection and reconstruction in post-intubation stenosis.

We assessed several factors which might be responsible for the recurrence of post-intubation airway stenosis in a large group of patients who underwent resection and reconstruction surgery by one surgical team. Four hundred and ninety-four patients underwent reconstruction of post-intubation airway stenosis during 1995-2006. The case group comprised patients who had developed recurrence, while controls had no recurrence. The diagnosis of the recurrence was made based on the presence of clinical signs or symptoms and bronchoscopic evaluation. The following variables were compared in both groups: age, sex, duration of intubation, reason for intubation, period of time between intubation and surgery, history of previous tracheotomy, previous therapeutic interventions, subglottic involvement, length of resection, presence of unusual tension at the site of anastomosis and anastomotic infection. Fifty-two patients (10.5%) developed recurrence. Lengthy resection, presence of tension at the site of anastomosis, anastomotic infection and subglottic involvement were significantly higher in the case group. Logistic regression model showed that the three main predictors are anastomotic infection (OR=3.44), subglottic involvement (OR=2.43), and presence of tension (OR=1.97), respectively. It is concluded that the surgeon can play an important role in avoiding recurrence by decreasing tension, preventing infection, and preserving subglottic structure.

Postintubation multisegmental tracheal stenosis: treatment and results.

BACKGROUND: A number of postintubation tracheal stenoses involve different and separate segments. Treatment of these types of strictures is complicated with obscure results, infrequently reported in literature. METHODS: A total of 648 patients underwent treatment for tracheal or subglottic stenosis from September 1993 through October 2005; of those, 26 cases had two separate stenotic segments. Four types of therapeutic approaches were considered for these 26 patients: one-stage resection of the stenotic sites; two-stage resection of the stenotic sites; resection of one stricture and treatment of the second one by nonresectional methods such as dilatation, laser, stenting, T-tube, or tracheostomy; or treatment of both lesions by nonresectional methods. The therapeutic approach for each patient was determined by the surgeon and was based on the nature and location of stenoses, length of stenoses and the distance between the two stenotic sites. RESULTS: There were 20 male patients (76.9%) and 6 female patients (23.1%), with a mean age of 23.9 years (range, 4 to 64). Fourteen patients had tracheal stenosis and 12 had both tracheal and subglottic involvement. Five patients underwent type 1 therapeutic approach whereas 4, 9, and 8 patients underwent types 2, 3, and 4, respectively. Mean length of resection was 58.9 mm in those who underwent complete resection of the stenotic sites (range, 30 to 90 mm). There were 2 complications, 1 stomal fistula and 1 wound infection. Follow-up was accomplished in all patients with a mean period of 21.5 months (range, 1 to 108). Sixteen patients achieved satisfactory results (good voice and airway), 7 are still under treatment (requiring stent, tracheostomy, or repeated dilatation), and 3 died (2 type 3 and 1 type 4). Two deaths were due to T-tube obstruction, and 1 was due to acute obstruction of the stenotic part. CONCLUSIONS: Resection of both strictures and reconstruction of airway are feasible in some patients with multisegmental tracheal stenosis with good results. When resection of both strictures is not feasible, a combination of resectional and nonresectional managements could be helpful for the vast majority of patients.

The anesthetic management of an intrabronchial escape of a hydatid's ruptured laminated membrane during rigid bronchoscopy.

We describe the anesthetic management of a case in whom a previously undiagnosed pulmonary hydatid cyst manifested as a large amount of intrabronchial fragmented pieces of laminated membrane suddenly and unexpectedly during diagnostic rigid bronchoscopy.